Tagged Questions

Questions about Mathematica's date and time functions.

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1
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0answers
80 views

How to create a complex variable from dated list values

Can anyone help me to construct a variable "PI" from values of variable x. Variable x represents a group of two time series rj and ri on equal dates(joined two dated lists with states).Variable x have ...
3
votes
1answer
51 views

How to speed up Min of DateObjects?

I'm in version 10.0.1 using a Dataset to do some plots and things. For one of the plots I need to get the minimum date of a some filtered set of the ...
2
votes
1answer
81 views

A possible bug with regard to DateObjects in Version 10?

Bug related to the Suggestion Bar Bug While getting used to the new data type Date Object in Version 10 I noted that there seems to be a bug which on my machine ...
1
vote
2answers
104 views

How to select states with equal times

Can anyone show me how to select the states that have equal times-dates. For example, i have two time series. First that have 10 observations, say from 2014/10/1 to 2014/10/10, and second that have 7 ...
5
votes
4answers
138 views

Change string date/time to be understandable for mathematica

I'm trying to convert a string of a data and time to be understandable for mathematica (I want to make time related plots). However, I can get my head around how to do this. For example: ...
2
votes
1answer
74 views

DateListPlot with multiple data sets and incongruous timelines?

I am using Mathematica to analyze some sales data for my company. (A copy of the available data is here.) We are trying to analyze the sales trends for each month by item. DateListPlot works well ...
6
votes
1answer
92 views

How to make several DateListPlot have the same scale?

I want to plot some weather data series. Unfortunately the series were collected in different episodes, from which some overlap. I would like to plot them as different plots in a column, but with ...
6
votes
5answers
353 views

Calendar view outline

How to compute the outline of a calendar month like this D3 example. (D3 is a functional language built on JavaScript developed at Stanford and used by New York Times to deploy interactive ...
0
votes
1answer
96 views

How to get an Excel-like surface plot with ListContourPlot3D

I'm trying to create an Excel like surface plot from an import of data from an Excel workbook. I get the data without issue. It is a set of percentages in bin ranges over a series of dates. I'd ...
1
vote
0answers
55 views

Make a table of changes in US coinage

I thought of an innovative use of Mathematica/Alpha that I think Stephen Wolfram would really love, but I can't figure out how to get it to work. The idea is to make a table that would chart the ...
8
votes
2answers
175 views

interpolating function over dates

I've got a bunch of readings at various dates and times. I'd like to be able to interpolate and then integrate over, say days. I can do this by converting my date/time to ...
6
votes
3answers
161 views

Timeline plotting: horizontal bars of time intervals

This text file logs the time that a process (identified by a number) changes state ("Brown", "Blue" etc.") ...
2
votes
1answer
56 views

Correct handling of milliseconds in a date time string

DateString[{2014, 5, 7, 13, 47, 44.760}, {"Year", "-", "Month", "-", "Day", " ", "Hour", ":", "Minute", ":", "Second", ".", "Millisecond"}] Returns ...
8
votes
5answers
207 views

How to do DateDifference on table items containing dates

I have a Table with data in form {{date}, value}: ...
7
votes
3answers
170 views

Different results with DateRange and LeapYearsQ in Mathematica 9 and 10

With Mathematica 9.0 for Mac OS X x86 (64-bit) (January 24, 2013) one could use DateRange[{2000}, {2010}, "Year"] to achive ...
1
vote
1answer
87 views

How to get matching starting dates for different `FinancialData` properties? [closed]

Why do the "Return" and "Volume" outputs of FinancialData differ? Consider the following ...
4
votes
1answer
62 views
8
votes
1answer
146 views

Bug in DateListPlot in Mathematica 10

Mentioned this already in an answer to a related question. DateListPlot in Mathematica 10 has a horrible bug: If two points have the same time coordinate, only one is plotted; the others are ignored. ...
8
votes
3answers
305 views

Does Mathematica have Month Range and Day range?

It is known that CharacterRange["a", "z"] gives list of characters from a to z. Does Mathematica have something similar for weekdays and months of the year? ...
1
vote
0answers
26 views

Updating values in a Dataset [duplicate]

I'm starting to work with datasets. They seem like a useful addition to Mathematica. However, there's one fairly major stumbling block I can't get over. How do I update data in a dataset? I have a ...
4
votes
3answers
161 views

How to get a list of days from July 4th to Oct 4th over a range of years

I'd like to create a list with days from the 4th of July to the 4th of October starting in July 1970 to the current date. I tried to use DateRange, but I'm a bit ...
0
votes
1answer
47 views

Export date with specified format

My problem is that I want use PGFplot in $\LaTeX$ to draw my graphs, which x axis is a date. Therefore the output file has to have one column "UTC time" (YYYY-MM-DD hh:mm:ss) and the second one is the ...
3
votes
2answers
101 views

Slow work of TimeSeriesWindow

I have financial data (list of time-values pairs). There are more than 13000 elements. ...
4
votes
1answer
70 views

Poor (network) performance of Interpreter[“Time”]

I was surprised to see that Interpreter requires external WR resources as this is not documented, at least not here. On a 3Ghz iMac, took ~half a minute to ...
1
vote
1answer
114 views

Addition and subtraction of TimeObjects in v10 [closed]

Documentation states that "TimeObject allows addition and subtraction of time quantities". I can see that subtraction is fine, (example from doc page) TimeObject[{16, 17, 21}] - TimeObject[{10, ...
3
votes
1answer
147 views

BarChart that lines up with dates in DateListPlot

I am trying to create a chart similar to the view offered by TradingChart, but with custom data not relating to finance. ...
7
votes
3answers
464 views

Friday the 13th related tables

This code ...
0
votes
1answer
81 views

Extract data from DateListPlot, limited by PlotRange

Extracting the points from a line in a ListPlot in this answer uses points = Cases[Normal@plot, Line[pts_] :> pts, Infinity]; This works in DateListPlot ...
3
votes
3answers
68 views

Alternatives to DateQ of Calendar Package

This answer notes that Calendar package has a function DateQ but the documentation suggests that the input is limited to a fixed ...
-5
votes
1answer
58 views

how to mean of day,month value

data={{{2006, 1, 1, 0, 0, 0.}, 326.492, {2006, 1, 1, 3, 0, 0.}, 323.08, {2006, 1, 1, 6, 0, 0.}, 314.223, {2006, 1, 1, 9, 0, 0.}, 314.361, {2006, 1, 1, 12, 0, 0.}, 322.048, {2006, 1, 1, 15, 0, ...
0
votes
1answer
80 views

Text with date, how to convert?

I use this script to recognise a date in a textfile and write the result in another file. ...
0
votes
2answers
120 views

How to partition three years of data into daily samples

I'm trying to find mean of temperature data list. The temperature data list has 3 hours steps which means I have 365*8=2920 temperature measurements per year. My data are temperatures of 13 years. ...
2
votes
0answers
85 views

DateList does not output the correct time, but Date does

I noticed a strange thing when trying the new astronomical data functions in Mathematica 10 on my Raspberry Pi. The Sunrise and ...
0
votes
2answers
105 views

Convert epoch seconds to date [duplicate]

I have got the following datetime from an API: 1395401384298 I am guessing it is in epoch miliseconds time (it should be one day in 2014) How can i convert it into a more readable String? I have been ...
2
votes
2answers
110 views

Counting Events in a moving date range

I want to count the number of times events take place in a date range. The counting is done over a window of e.g. 28 days where the goal is to have between 11 and 13 events in the time window. The ...
1
vote
2answers
83 views

I'm trying to filter a date range by day of month and day of week - what am I doing wrong?

I am trying to generate a list of dates that match two criteria: they have to all be the first of the month, and they have to be a particular day of the week, Sunday in my case. The code I have ...
1
vote
1answer
155 views

Splitting dates into groups in half year steps

list = DayRange[{1999, 1, 1}, {2014, 2, 6}] I want to split this list into sublists one and a half year long, moving a half year forward every time. That would ...
3
votes
4answers
199 views

Finding the location of the last day of the month in a list of dates

My question differs from earlier questions about getting the eom dates from a list; I want to get the position of those dates so I can get the corresponding values from other lists. My problem seems ...
5
votes
4answers
380 views

How to Merge Date and Time?

Given the following time series data where row is date and column is time intervals. ...
9
votes
1answer
193 views

ScheduledTask with scoped variables. Working with timed evaluation

I guess I have to try harder and focus more but timed evaluation always frustrates me. I will show the issue on simple example of delayed trigger. ...
2
votes
2answers
109 views

Converting a date to a calendar quarter

I have a list that includes dates. I need to convert each date to be the last day of the quarter that it's in. So for example I want {2013,7,1,0,0,0} to become {2013,9,30,0,0,0}. Actually I don't ...
4
votes
2answers
147 views

How to change start and end date of DateListPlot with Manipulate?

Let's say I have a one dimension list d with length L. The $x$-axis in the plot starts from ...
5
votes
1answer
110 views

Why DateDifference returns machine number?

Is there any specific reason why DateDifference cannot give an exact number in this case? ...
5
votes
2answers
128 views

How can AbsoluteTimes be split by date faster?

I have data where the date is stored as an AbsoluteTime. Here's a dummy dataset: ...
4
votes
0answers
84 views

JewishNewYear date limitation

The documentation for the function "JewishNewYear" in the "calendar" package declares that the year argument must be between 1900 and 2100. No explanation is given for this limitation. The function ...
6
votes
2answers
967 views

Measuring execution time of code

How one can measure the execution time (time that is spent for code to finish) of a program in Mathematica? I understand that there are general timing functions (Timing, AbsoluteTiming, TimeUsed, ...
4
votes
1answer
379 views

UNIX time to DateList

I have data that is timestamped with UNIX time, which is the number of seconds since January 1, 1970 UTC. Unfortunately, it seems that most of the date and time functions in Mathematica are based on ...
39
votes
1answer
883 views

How can I manipulate TemporalData?

Version 9 introduced TemporalData but, truth be told, the documentation doesn't suggest that one can do much with it. Many of us have probably assumed we'd be ...
3
votes
4answers
229 views

Test whether date is in a certain period

I have one table which contains time periods ("start" and "end") and a "type" for every ...
3
votes
2answers
189 views

WeatherData for the 15th day of each month

Suppose we have WeatherData["Helsinki", "MeanTemperature", {{2007, 1, 1}, {2012, 12, 31}, "Day"}] How we can have data just for 15th day of each month?